Rename update-test-expectations -> update-flaky-expectations

Hi bokan@, what do you think of this possible rename?

Review-Url: https://codereview.chromium.org/2895863003
Cr-Commit-Position: refs/heads/master@{#473967}

third_party/WebKit/Tools/Scripts/update-test-expectations → third_party/WebKit/Tools/Scripts/update-flaky-expectations

@@ -7,7 +7,7 @@
 import sys
 
 from webkitpy.common import host
-from webkitpy.layout_tests import update_test_expectations
+from webkitpy.layout_tests import update_flaky_expectations
 from webkitpy.layout_tests.layout_package.bot_test_expectations import BotTestExpectationsFactory
 
 if __name__ == "__main__":

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_test_expectations_unittest.py → third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/update_flaky_expectations_unittest.py

@@ -12,8 +12,8 @@ from webkitpy.common.system.log_testing import LoggingTestCase
 from webkitpy.layout_tests.builder_list import BuilderList
 from webkitpy.layout_tests.port.factory import PortFactory
 from webkitpy.layout_tests.port.test import LAYOUT_TEST_DIR
-from webkitpy.layout_tests.update_test_expectations import main
-from webkitpy.layout_tests.update_test_expectations import RemoveFlakesOMatic
+from webkitpy.layout_tests.update_flaky_expectations import main
+from webkitpy.layout_tests.update_flaky_expectations import RemoveFlakesOMatic
 from webkitpy.tool.commands.flaky_tests import FlakyTests